Abstract Anxiety disorders are the most common form of psychopathology, frequently begin in childhood, and are often associated with substantial lifelong impairment. Thus, there is a critical need and opportunity to identify neural markers of risk that distinguish anxious from healthy trajectories early in development that may serve as novel targets for intervention ? especially if they are evident before symptoms have become impairing. One promising neural marker of anxiety is increased brain activity in response to mistakes, as reflected by the error-related negativity (ERN). Considering that the ERN is elevated before anxiety symptoms become impairing, it is critical to identify environmental factors that may shape the ERN early in life ? so that those factors can be manipulated to reduce the ERN and potentially mitigate risk. In a sample of 295 six-year old children, we found that both observational and self-report measures of harsh parenting style related to an increased ERN in offspring. A similar pattern of results was reported by another lab amongst 4 year-old children. Moreover, results suggested that the ERN mediated the relationship between harsh parenting and child anxiety disorders. Based on these data, we propose to develop a novel psychosocial intervention to be administered to both parents and children, which aims to normalize the ERN in children (i.e., reduce over-reactivity to making errors). The proposed Mentored Career Development Award (K01) is designed to extend my previous work on the ERN, parenting, and risk for anxiety in young children to test the extent to which the ERN can be modulated. Specifically, we will recruit 175 parent/child dyads, high in error sensitivity, and randomize 25 to a control condition, 50 to a parent only condition, 50 to a child only condition, and 50 to a parent/child condition. We will measure the ERN in children pre and post intervention, as well as baseline anxiety symptoms. At a six-month follow-up, we will assess children?s ERN, as well as anxiety symptoms. Moreover, my training plan builds on my expertise on the ERN and anxiety, and integrates expertise in the design and implementation of computerized interventions, as well as advanced statistical analyses related to intervention outcomes.